Laminar covering material

ABSTRACT

A covering material, such as a flooring, comprises a layer of resilient material, for example rubber-based material, and a plane metal reticular structure, for example made of aluminium, coupled to the layer of resilient material. The metal reticular structure is at least partially emerging at the surface of the layer of resilient material. Provided on the side of the layer of resilient material opposite to the plane metal structure is a balancing layer, for example in the form of a network of fibres, such as glass fibre. Preferentially, the balancing layer has associated to it an outer layer of geotextile material and/or material in the form of felt.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from European Patent Application No.05425587.2, filed on Aug. 9, 2005, the entire disclosure of which isincorporated herein by reference.

TECHNICAL FIELD

The invention relates to laminar covering materials that can be used,for example, for providing floorings such as floorings for civilapplications, and in particular for “industrial” applications. The term“industrial” is here meant, in general, to refer to floorings that areexposed to conditions in which there is a lot of coming-and-going ofpeople or that are subject to extensive wear (for example, airports,railway or bus stations, underground stations, commercial centres,etc.). In particular, the invention relates to a laminar coveringmaterial that can be made with a resilient material, such as a materialfor “resilient floorings”.

BACKGROUND OF THE INVENTION

The term “resilient flooring” or “resilient floor covering” is intendedto indicate the types of resilient flooring identified according to theCEN/TC134 Committee operating in the framework of the European StandardsCommittee, and in particular the types of flooring identified in theEN650 standard. It refers therefore, according to the currentacceptation of the term, to resilient floorings made with materialscomprising, for example, natural, synthetic, and artificial rubbers,artificial and synthetic resins (for example, polyolefin-basedmaterials, PVC-based materials, and the like), as well as materialshaving a particular composition, such as for instance linoleum.

The known art regarding floor-covering materials of this type isextremely extensive, as certified, for example, by the documents Nos.U.S. Pat. No. 4,772,500, U.S. Pat. No. 5,217,554, U.S. Pat. No.5,899,038, US-A-2003/006522, U.S. Pat. No. 6,391,381, U.S. Pat. No.6,418,691, U.S. Pat. No. 6,809,144, US-A-2005/006809 andUS-A-2005/065236, all assigned in ownership to the assignee of thepresent patent application.

In the production of covering materials (and in particular materials forfloorings) of the type described herein, it is necessary to take intoaccount requirements of various nature, which, in effect, frequentlycontrast with one another.

One of the most deeply felt requirements is that of providing coveringmaterials that are able to combine an attractive aesthetic appearancewith qualities of high resistance to wear, low deformation even underheavy loads, dimensional stability (in particular, conservation of thecharacteristics of planarity over time), absence of phenomena ofdetachment from the laying substrate, together with characteristics oftread that are completely satisfactory (good anti-slip performance, lownoise).

The impossibility of satisfying all these requirements in an ideal waymeans that, at least for some applications, the choice of the users isoriented towards covering materials of a different type (in general, ofa more traditional type) such as, for example, ceramic, marble and/orstone coverings and floorings, said covering materials in turn not,however, being without some major drawbacks, such as, for example, theweight (which renders far from readily proposable, for example, the useof said materials on board vehicles), the risk of failure and ofcracking in the presence of possible deformations or vibrations of thelaying substrates (which, once again, renders problematical the use offloorings of this kind on board mobile structures or also within civilstructures in areas exposed to the risk of earthquake).

SUMMARY OF THE INVENTION

The object of the present invention is to provide a covering that isable to solve in an ideal way the problems linked both to the use ofresilient materials and to the use of the alternative materialsconsidered previously, the aim being to provide a covering material thatis able to combine the characteristics of high aesthetic quality and ofresistance to the stresses due to tread of some traditional materialswith the qualities of performance (in particular, treading “comfort”)and of low weight traditionally recognized to coverings with a base ofresilient materials.

According to the present invention, the object above is achieved thanksto a covering material having the characteristics referred tospecifically in the ensuing claims.

Essentially, the solution described herein is based upon recourse to acombination between a metal material (in particular, in the form of areticular structure) and a resilient material. This combination is notin itself new to the art; it is extensively used, for instance, in theproduction of conveyor belts, and in the automotive industry for makingtyres and components such as sleeves, anti-vibrating elements and thelike, in which an elastomer is combined with a structure of metalreinforcement, typically having a reticular structure.

The above “Technological” solutions usually contemplate, however, thatthe metal reinforcement structure is kept in a hidden (“embedded”)position with respect to the mass of elastomer material, seeking ratherto contain as far as possible any risks of exposure of the metalstructure with respect to the metal/elastomer composite material.

The solution described herein moves, instead, in the exactly oppositedirection and is based upon the recognition of the fact that—in analtogether surprising and unexpected way—the, at least partial, exposureof the reinforcement metal structure on the outer surface of thecovering bestows upon the covering material excellent characteristics ofresistance to wear, low deformation even under heavy loads, dimensionalstability (in particular, conservation of characteristics of planarityover time), absence of phenomena of detachment from the layingsubstrate, together with altogether satisfactory characteristics oftread (good anti-slip performance, low noise).

Added to the above is an appreciable high aesthetic quality without thishaving any adverse effect on the intrinsic qualities demonstrated bycoverings with a base of resilient material. This regards in aparticular, but not exclusive, way the possibility of altogetherlimiting undesirable phenomena of detachment between the metalreinforcement structure and the resilient material.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described, purely by way of non-limitingexample, with reference to the annexed plate of drawings, in which:

FIGS. 1 to 3 illustrate successive steps of a method for theconstruction of a covering material of the type described herein; and

FIG. 4 illustrates schematically, in a partially cut-away view, thecharacteristics of the material described herein.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 of the annexed plate of drawings illustrates, as representing oneof the initial steps of the method described herein, the step ofproviding a structure made of a metal material represented typically bya network, lattice or grid 1 of metal material.

Even though this choice is not imperative, the choice of reticularstructures consisting of a deformable metal material, i.e., structurespresenting qualities of ductility and malleability, is believed to beamply preferable. A currently preferred material is represented byaluminium. The values of mass per unit area of the network, fabric orlattice-like structure range preferably between 250 and 1250 g/m²approximately, a particularly preferred value being around 750 g/m².

The expressions “approximately” and “around”, as used herein, areevidently intended to take into account the tolerances normallyassociated to the construction and to the measurement of the quantitieseach time considered.

The conformation of the meshes of the network or lattice does not initself constitute a binding parameter. The choice currently preferred isthat of networks with a flattened rhomboidal mesh (i.e., with each meshhaving the shape of a rhombus) or a flattened hexagonal mesh.

Reticular metal structures of this type are commonly available in theart for various applications. A field in which extensive use of networks(grids or lattices) of this type is made is the automotive sector, wherethese networks are used, for example, to make protective grills forfilters, ventilation intakes and openings or ducts of various nature.Networks or lattices of this type are widely used also in the buildingsector.

5The dimensions of the meshes of these structures are usually identifiedby two values (DL and DC), which correspond to the values of the maximumand minimum “diagonals” of the mesh. For the purposes of the solutiondescribed herein values of major diagonal DL approximately between 5 mmand 25 mm are considered preferable, the preferred range being between10 mm and 15 mm approximately, a particularly preferred value beingaround 10 mm. Likewise values of minor diagonal DC of between 3 mm and13 mm approximately are considered preferable, the preferred range beingbetween 5 mm and 6.5 mm approximately, a particularly preferred valuebeing around 5 mm. In a preferred way, the aforesaid ranges/values areto be considered co-ordinated with one another.

It will likewise be appreciated that the term “reticular structure” isherein used in its widest acceptation, and thus comprises within itsscope also structures consisting of parallel filiform elements or elsestructures consisting of filiform elements that evolve according tovolutes of various nature.

In the most typical form, which is that of a network consisting ofregular meshes, these structures are usually obtained starting from astrip of sheet metal that is simultaneously undulated and notched so asto form a regular array (for example, a quincunx) of transverse slitsand then stretched out so as to create the network structure.

In the majority of applications, this method means that the reticularstructure obtained is not present exactly plane but is constituted bybranches that extend, at least in part, in a direction at leastmarginally angled with respect to the general plane of extension of thereticular structure.

FIG. 2 illustrates a step of treatment, in which a reticular material 1such as the one represented in FIG. 1 is subjected to an operation offlattening performed in an opposed-roller apparatus basically resemblinga calender P. The aim of this flattening treatment is to arrive at areticular structure 2 flattened having an overall plane development anda thickness in the region of 0.3-2 mm, approximately.

The plane reticular structure 2 thus obtained is then coupled, in thestep schematically represented in FIG. 3, to one or more layers 3 ofmaterial for resilient floorings or resilient floor coverings, accordingto the specific acceptation of this term recalled in the introductorypart of the present description.

Before proceeding to said coupling operation, the metal reticularstructure 2 subjected to flattening is treated, at least on the sidethat is to be coupled to the resilient material 3, with a so-called“primer”, i.e., with a material functioning as promoter of adhesionbetween the metal material of the structure 2 and the resilient material3 to which said structure is to be coupled.

Promoters of adhesion that can be used in an altogether satisfactory wayin the context described herein are available under the commercial nameof CILBOND® produced by Chemical Innovations Limited of Bamber Bridge,England. Assuming, for example, that the metal material of the structure2 is aluminium, and the resilient material 3 consists of rubber (eithernatural or synthetic, such as for example SBR) the aforesaid promoter ofadhesion or primer, designated schematically by 4, may be the productCILBOND® 24.

After application of the primer 4 (performed in a station designated byB, operating according to known techniques), the metal structure 2 andthe resilient material 3 are coupled to one another according to one ofthe typical methods used for the production of laminar coveringmaterials with a base of resilient materials.

For example, the resilient material 3 may be of a stratified type andcomprise two or more layers 3 a, 3 b, for instance of a rubber-based mixwith different formulation, for example for optimizing the ratio ofconnection/adhesion with the adjacent layers.

The method of coupling in question can be performed by resorting toknown technologies that envisage the simultaneous application ofpressure and heat to the composite material constituted, in the specificcase considered herein (see FIG. 3), by the metal reticular structure 2and by the resilient material 3.

In the case in point, in FIG. 3 the reference R designates a pair ofcounter-rotating rollers that couples the various layers of thecomposite material, whilst the reference RC designates as a whole amachine for the simultaneous application of pressure and heat to thecomposite material in question. The equipment in question can betypically constituted by a continuous press or an isostatic press, bothof a known type.

The construction of the composite material described herein involves ina preferred way the application, on the side of the layer of theresilient material 3 opposite to the plane metal structure 2, of one ormore stabilization layers.

A typical example of such a stabilization layer consists of a network 5made of glass fibre (with mass per unit area, for example, of from 25 to100 g/m² approximately, with a preferred value of around 50 g/m²), thefunction of which, in the context of the composite product obtained, isto create a balanced metal/resistant-material/reinforcement-fabricstructure that can minimize undesirable phenomena of deformation of thestructure thus obtained.

Combined with the network 5, on the outer side with respect to thecomposite material, there may be a further layer of material 6, such asfor example a geotextile material and/or a material in the form of felt(with mass per unit area, for instance, of 80 to 300 g/m² approximately,with a preferred value of around 200 g/m²). A felt of this type, madefor example with a base of polyester and/or polypropylene, is able tofacilitate application of glues for laying of the flooring and the firmconnection of the covering material thus obtained (designated as a wholeby 7) on an application substrate.

As already mentioned in the introductory part of the presentdescription, the material 7 takes the form of a composite metalmaterial/resilient material in which the reinforcement metal structure,instead of being embedded within the composite material, is completelyexposed or else at least marginally emerging from the outer surface ofthe composite material 7, i.e., the surface exposed to severe treatmentduring use: in the case of a flooring, said outer surface is evidentlyconstituted by the upper surface of the flooring, which is exposed totread.

The degree of exposure/surfacing of the metal structure 2 with respectto the aforesaid outer surface can be conveniently adjusted—all otherprocess parameters being equal—by adjusting the pressure applied to thecomposite material during its formation in the equipment designated byRC in FIG. 3.

The material 7 obtained with the method just described is configuredthen as schematically represented in FIG. 4, i.e., as a material inwhich the “body” layer consists of a resilient material 3 (such asrubber, possibly with stratified structure 3 a, 3 b) and the outersurface of which, exposed to tread and to wear, is reinforced by thepattern of the metal structure 2 that surfaces in a complete or at leastpartial way on the aforesaid outer surface, whilst the primer 4 ensuresintimate connection between the metal structure 2 and the resilientmaterial 3, totally preventing the undesirable creation of areas of(micro)detachment between the metal structure 2 and the resilientmaterial 3.

Albeit without wishing to be tied down to any specific theory in thisconnection, the present applicant has reasons to believe that the(complete or partial) surfacing of the metal structure 2 on the outersurface of the composite material thus obtained means that the metalstructure 2 amply absorbs the stresses that, in a resilient flooring ofa traditional type, tend to be discharged on the resilient material.From this fact there derive the characteristics of resistance to weardemonstrated by a covering material of the type described above.

At the same time, the material in question presents good characteristicsof compliance, i.e., of resilience. This also in view of the fact thatthe metal structure 2 is not completely rigid and has, instead, aboveall in the case where it is made with a material such as aluminium, goodcharacteristics of deformability and of resistance to vibration and tothe stresses possibly linked to a deformation of the laying substrate.

The material may be made in a laminar form with small thicknesses (forexample, with thicknesses typically of between 1.8 mm and 4 mm, typicalof coverings made of resilient material) with a containment of theweight per unit surface to values considerably smaller than thehomologous values of materials, such as ceramic or stone materials. Itwill, on the other hand, be appreciated that the solution describedherein is suited also to the creation of the laminar material 7 withlarger thicknesses (thicknesses of around one centimetre), with thepossibility of making the material available in the form of tiles.

Added to these considerations of a technical nature are alsoconsiderations of an aesthetic nature: the emerging metal structure 2 isable to contribute, with its colouring (and its typical metallicappearance), to the high aesthetic quality of the flooring, it beingalso possible, for the purposes of the overall colouring of thecovering, to play on the range of chromatic choices—which arepractically infinite—allowed for the resilient material.

Of course, without prejudice to the principle of the invention, thedetails of construction and the embodiments may widely vary with respectto what is described and illustrated herein, without thereby departingfrom the scope of the present invention, as defined by the annexedclaims.

1. A laminar covering material comprising: a layer of resilientmaterial; and a plane metal reticular structure coupled to said layer ofresilient material; said metal reticular structure at least partiallyemerging at the surface of said layer of resilient material.
 2. Thematerial according to claim 1 wherein said metal reticular structureemerges completely at the surface of said layer of resilient material.3. The material according to claim 1 further comprising a promoter ofadhesion or primer set between said plane metal reticular structure andsaid layer of resilient material.
 4. The material according to claim 1wherein said metal reticular structure is a completely plane structure.5. The material according to claim 1 wherein said plane metal reticularstructure is made of deformable metal material.
 6. The materialaccording to claim 1 wherein said plane metal reticular structure ismade of aluminium.
 7. The material according to claim 1 wherein saidplane metal reticular structure has a mass per unit area of betweenaround 250 and around 1250 g/m².
 8. The material according to claim 1wherein said plane metal reticular structure has a mass per unit area ofaround 750 g/m².
 9. The material according to claim 1 wherein said planemetal reticular structure has meshes with a flattened rhomboidal orhexagonal shape.
 10. The material according claim 1 wherein said planemetal reticular structure has meshes with values of major diagonal (DL)of between around 5 and around 25 mm.
 11. The material according toclaim 1 wherein said plane metal reticular structure has meshes withvalues of major diagonal (DL) of between around 10 and around 15 mm. 12.The material according to claim 1 wherein said plane metal reticularstructure has meshes with values of major diagonal (DL) of around 10 mm.13. The material according to claim 1 wherein said plane metal reticularstructure has meshes with values of minor diagonal (DC) of betweenaround 3 and around 13 mm.
 14. The material according to claim 1 whereinsaid plane metal reticular structure has meshes with values of minordiagonal (DC) of between around 5 and around 6.5 mm.
 15. The materialaccording to claim 1 wherein said plane metal reticular structure hasmeshes with values of minor diagonal (DC) of around 5 mm.
 16. Thematerial according to claim 1 wherein said resilient material is chosenin the group consisting of rubbers, artificial and synthetic resins, andlinoleum.
 17. The material according to claim 16 wherein said resilientmaterial is a rubber-based material.
 18. The material according to claim1 further comprising on the side of said layer of resilient materialopposite to said plane metal reticular structure, a balancing layer. 19.The material according to claim 18 wherein said balancing layer is inthe form of a network.
 20. The material according to claim 18 whereinsaid balancing layer comprises glass fibres.
 21. The material accordingto claims 18 wherein said balancing layer has associated to it at leastone of an outer layer of geotextile material and a material in the formof felt.